China’s valve industry, although in recent years expanded faster, but still low overall level of the industry, products with low technological content, and many key parameters of high valve still rely on imports. Some experts estimate, the level of our valves to 10~20 years behind compared with advanced foreign country. Not long ago, China’s valve industry to strengthen the Cast Iron Butterfly Valve manufacturing industry and the European exchanges, has organized more than 10 domestic valve enterprises Mister trip to Europe, learned many valuable experience of foreign counterparts, while the valve industry compared with foreign, also see our own lack of.
The gap process in the welding process, the German KSB company to meet the radiation nuclear valves sealing material against supplications, has been widely used in special welding of cobalt free solder powder suspension; France Wieland valve company will preheating before welding, automatic welding, after welding treatment in the same equipment or the same production line, whether before welding, welding, after welding in the disposal, temperature can complete the automatic control, to ensure the welding quality. In the valve on the domestic welding process backward, and some also used the old method of welding, welder low level of technology, the welding material and common material, not up to a special Integral Seat Pressure Seal Bonnet Globe Valves
design request. Many enterprises engaged in production and sales all day, very few improvements in the technique on the study of suspension.
In forging the use of new technology, the German company KSB consumption material to high temperature alloy steel F91, F22 based, while the high-pressure valve Youyi forgings mainly, to ensure the reliability and economy. Of the large volume following valve 600Lb using forging and welding, the valve is not caused by casting suspension, and holes, and many other defects, and greatly reduce the free forging of material waste, economy greatly step.
But the domestic industry mostly rough pieces of multi casting, forging the little used, more can be said in the following high pressure valve 600Lb forging very rare. Many companies in this regard in order to reduce costs, mostly by steel casting, low pressure cast iron pieces and more material, low cost, simple processing technology.
The gap between process management
France Wieland equipment layout according to the product craft road stop, to arrive at the process route is the shortest, so the operator can be machined in the smallest actions completed within. Flexible machining center they used a lot of that five axis machining center, CNC milling machines and CNC machine tool, the computer aided manufacturing a line, the product once clamping, a programming device. The programming work that remotely in the office, this simplifies the machining process, engineering and technical personnel only need to have written the program, select the suitable tool, can guarantee the processing for products, and make products with high quality and high efficiency.
Similarly, the consumption process characteristics of Italy Nuovo Pignone is: after receiving the order, the transformation from design and development centers, providing product design drawings, details of foreign outsourcing agreement, machining procedures, technical documents, through the internal network to the relevant departments, according to the technical requirements of the consumer sector and sales order group consumption. Blanks into the plant, the Kuguan officers under the spending plan will be blank and the other parts of the parts sent to the processing, assembly sites, not all of their own consumption, many are purchasing. But they almost all product components are finished on CNC equipment, high machining accuracy, processing efficiency is very high. Employees work station in CNC machining equipment can be access to parts processing maps and spare parts processing, he only need to press the processing technology for the workpiece clamping to the numerical control device, start the processing, it can automatically complete vehicles, drilling, milling, boring and other machining processes.
The quality gap between management and equipment
France Bernard electric Devices Corporation 2005 annual sales of 300000000 Yuan, exports accounted for 70% of sales, set a global sales network, China’s metallurgy, papermaking, water treatment and oil and gas pipeline valve uses a lot of electronic products in the company. In the nuclear field, their supply is ranked second in the world, France has 70 nuclear power plants to use their products. Their management is in place, the company recorded a single with the machining of parts with circulation, consumption field uniform, tidy, two assembly lines in order to work. They use rolling way screw machining, high efficiency, high brightness light surface parts. Parts cleaning disposal processed timely, station apparatus applied correctly, such as the axis of each set in a plastic bag, very simple, but very useful, to avoid part of the collision between the scratch. Coating methods of parts and almost domestic, but because of its smooth and rough excellent quality paint, spray paint the future products, the appearance and quality of results is quite good.
In contrast, the domestic quality management there are still many shortcomings, first of all more or less ignored in the process, many businesses have quality assurance system obviously, but theoretical work did not play, quality management to execute go one’s own way, arbitrary; second, in the assembly process is sloppy. No wonder some of the valve installed on the present run, run, drip, drain phenomenon.
Another example is a lot of domestic enterprise production equipment behind, still stuck in the last century 70~80 age level, some equipment had a useful life period, is still running at full capacity, product quality and can guarantee? Some limited funds, but also being acquired and CNC machining centers, but the composition of NC processing enterprises has not many in the industry, accounting for only about 20%.
And a lot of natural gas domestic enterprises valve is not professional, small and complete, the product mix, process valve disorders, planning workshop equipment spare parts stacked unreasonable, not concentrated. Currently widely used piece working hours, but also the disadvantages, unreasonable work hours, most still use the original manual records summary settlement. It is because of some restrictions on business process management level, lead to the low level of product technology, processing technology lags behind, the raw material waste.
In addition, the process of domestic mechanical processing equipment layout mostly by equipment type suspension layout, furnishings such as machining centers, horizontal placed in a row, standing on a row, put a row of CNC machine tools, such arrangements only considering field uniform, without thinking of convenient operation, labor efficiency is low, far away.